Has anybody used Delta Chat?

Usually when alternatives for messaging apps are recommended it's Signal, Threema or Element but all of them still seem to have small inconveniences (Signal is American, Threema isn't free and Element just seems too complicated).

Today I stumbled upon Delta Chat for the first time and it seems to be the ideal solution. It's european, free, open-source, decentralised, usable on almost any device and privacy focused. But the fact that I've never heard about it before makes me hesitant.

Has anyone of you used it and can share their experience?

Edit: Here's a link to their official website: https://delta.chat/en/